Orbital Path Podcast: The 11 Dimensions of Brian Greene

In this episode of Orbital Path, we hear from Brian Greene on the coming paradigm shift in physics as current theories fail to adequately explain quantum entanglement.

World Science Festival / Greg Kessler

It all started by counting on our fingers. You could keep track of how many cows you had, or how many how many apples to trade for a basket of eggs. Count up to ten, then place a marker and start over, and you could count the days for the Moon to come around to the same shape again or how many days until the weather turned colder. Mathematics is a simple human behavior. But it turned out that mathematics was also a journey, a road we began to walk along with no idea where it might lead. As Bilbo said to Frodo in Tolkien’s Lord of the Rings, “It’s a dangerous business, Frodo, going out of your door. You step into the Road, and if you don’t keep your feet, there is no knowing where you might be swept off to.”

At this moment in modern physics, we have been swept off to a universe that seems quite alien from the one we experience. We are aware of four dimensions of reality, there dimensions of space and one of time. But most physicists, for the last hundred years, have needed additional dimensions to account for the subtleties of gravity, or the complex interactions of the tiny particles that make up matter. Einstein hinted at higher dimensions when he described gravity as a bending of space and time. String theory, which, linked with quantum mechanics, is the most complete description of the behavior of elementary particles, requires no less than eleven dimensions of space and time for the mathematics to work. A central tenant of string theory is that all the different elementary particles we observe in our universe, from quarks to photons to positrons, all have an underlying common make-up. All can be visualized as strings, or sometimes membranes like the skin of a drum, that vibrate in different modes and frequencies. In some ways, every particle of the universe is made up of the same stuff, it’s just that the stuff is vibrating differently. And why eleven dimensions? Simple: the equations needed that many terms, that many directions for the strings to vibrate, to make the predictions of the theory match reality.

But here’s the thing: the math behind string theory works beautifully, making extremely accurate predictions of the behavior of everything from atoms to the relative strengths of the natural forces. Eleven dimensions works so well. But is this real? Really real? Not just some convenient trick of mathematics? Where are the extra seven dimensions and why do our brains only perceive a tiny fraction of reality?

In my mind, the foremost person in the world to talk to about this is Professor Brian Greene at Columbia University. A renowned theoretical physicist, Greene has also written several best-selling books about the origins and implications of string theory, including The Elegant Universe, The Fabric of the Cosmos, and The Hidden Reality. He’s done TED talks about string theory and the idea of multiple universes which were both clear and mind-blowing at the same time. In my opinion, Greene is the go-to person to ask about how one even starts to think about an eleven-dimensional universe, and I was gobsmacked to have the chance to speak with him for this episode of Orbital Path.

I had some more pressing personal questions for him too, as I had attended a scientific colloquium he gave at NASA’s Goddard Space Flight Center a few years ago. This talk was meant for an audience of scientists, so he got a bit more into the mathematical weeds than he usually does during public presentations. My husband was sitting next to me in the auditorium and he felt me literally trying to stop from jumping up and down as Greene showed us a bit more detail about the math; how the complex mathematical chaos of different competing versions of particle physics all settled down and behaved beautifully if you just allowed the universe the freedom to vibrate in eleven dimensions. It was thrilling.

Greene also hinted at something deeper; he feels there will soon be a huge change in our understanding of the universe. Einstein’s gravity is more than a century old now, and the basic ideas of string theory have not changed much in the last decades. But Greene thinks a revolution is just over the horizon. The problem and promise in modern physics is a phenomenon called quantum entanglement, where two particles respond to each other’s conditions instantaneously, even over great distance (the Chinese were recently successful in entangling two particles, one on Earth and one on a satellite –a distance of 1200 km). None of our current descriptions of particles physics, including string theory, deal very well with this now common-place experimental result. And Greene feels that soon, all our current ideas about the nature of reality might fall apart and re-arrange themselves back again around the core of quantum entanglement. When this happens, we may be asked to leave behind even the idea of the existence of space and time.

This road has taken us to a place we had no intention of going, and for the time being, we well may be lost. But here’s the thing; roads tend not to lead nowhere. They are built and followed for a reason, even if we can’t see what’s around the bend right now. Like Frodo, we just need the courage to keep putting one foot in front of the other and see where the road leads.


Orbital Path is produced by PRX and supported by the Alfred P. Sloan Foundation. Don't miss PRX's other science podcasts: Transistor and Outside Magazine.

10 thoughts on “Orbital Path Podcast: The 11 Dimensions of Brian Greene

  1. RussRuss

    Wow, Michelle! I just listened to this podcast and came away feeling like you described – my feet not quite touching the ground. While I am not a scientist or mathematician, I did study physics, graduating in the late 1960’s. While the math was difficult and many times hard to grasp from a real world perspective, I came away from that learning experience with an appreciation for mathematics. In my mind I thought that if I saw an object (flag, bird-feeder, etc.) swinging in the breeze, it would be possible to describe its motion with a set of mathematical equations.

    Now almost 50 years later, not having pursued a career in math or science, my mathematical skills are quite rudimentary. Yet there is still the appreciation that even if we can’t understand the actual mathematics (i.e. the equations) they can still be used to describe the real world and make predictions that can be tested by experiment.

    So that podcast was a wonderful effort to help me (and other non-mathematicians, non-scientists) to understand the universe as described and predicted by sting theory. Once again I’m really with my feet barely touching the ground, I’m all energized with a new understanding about what the reality of the universe might really be.

    Thanks to Brian Greene for his wonderful effort in helping us understand a very complex, but beautiful subject! Thanks to you for asking the questions that help him to do so.!

    1. philip-gardner

      Not being a mathematician, I was wondering if spooky action at a distance or entanglement in quantum physics could travel on gravitational waves? Are these less than a proton in amplitude? Be nice to connect quantum with relativity. PG

  2. xinhangshen

    String theories are just mathematical games, nothing to do with reality. Even all electromagnetic theories and quantum mechanics are wrong theories because they have not taken into account the effects of aether – a compressible viscous fluid filling up the entire visible part of the universe. The existence of aether is a natural conclusion from that Einstein’s relativity theory has already been disproved both logically and experimentally (see “Challenge to the special theory of relativity”, March 1, 2016 on Physics Essays and a press release “Special Theory of Relativity Has Been Disproved Theoretically” on Eurekalert website: https://www.eurekalert.org/pub_releases/2016-03/ngpi-tst030116.php ). The problem of Einstein’s relativity is that it has redefined time and space through Lorentz Transformation. The newly defined time is no longer the physical time measured with physical clocks, which can be easily demonstrated by the following thought experiment of candle clocks:

    There are a series of vertically standing candles with the same burning rate and moving at different constant horizontal velocities in an inertial reference frame of (x, y, z, t) where x, y, z, t are relativistic positions and time. At any moment t of relativistic time, all candles have the same height H in the reference frame of (x, y, z, t) and the height has been calibrated to physical time as physical clocks. Therefore, we have the simultaneous events of the observation measured in both relativistic time and physical time in the frame of (x, y, z, t): (Candle1, x1, y1, H, t), (candle2, x2, y2, H, t), …, (CandleN, xN, yN, H, t). When these events are observed on anther horizontally moving inertial reference frame (x’, y’, z’, t’), according to special relativity, these events in the reference frame of (x’, y’, z’, t’) can be obtained through Lorentz Transformation: (Candle1, x’1, y’1, H, t’1), (Candle2, x’2, y’2, H, t’2), … , (CandleN, x’N, y’N, H, t’N) where t’1, t’2, …, and t’N are relativistic times of the events in the frame of (x’, y’, z’, t’). It is seen that these events have different relativistic times after Lorentz Transformation in the frame of (x’, y’, z’, t’), i.e., they are no longer simultaneous measured with relativistic time in the frame of (x’, y’, z’, t’), but the heights of the candles remain the same because the vertical heights here do not experience any Lorentz contraction. Since the heights of the candles are the measures of the physical time, we can see these events still have the same physical time, i.e., they are still simultaneous measured with the physical time. Therefore, the physical time is invariant of inertial reference frames, which is different from relativistic time. As relativistic time is no longer the physical time we measure with physical devices, the description of special relativity is irrelevant to the physical world.

    Now let’s have a look at the symmetric twin paradox. Two twins made separate space travels in the same velocity and acceleration relative to the earth all the time during their entire trips but in opposite directions. According to special relativity, each twin should find the other twin’s clock ticking more slowly than his own clock during the entire trip due to the relative velocity between them because acceleration did not have any effect on kinematic time dilation in special relativity. But when they came back to the earth, they found their clocks had exact the same time because of symmetry. Thus, there is a contradiction which has disproved special relativity. This thought experiment demonstrates that relativistic time is not our physical time and can never be materialized on physical clocks.

    Now let’s look at clocks on the GPS satellites which is thought as one of the strong evidences of Einstein’s relativity. Many physicists claim that clocks on the GPS satellites are corrected according to both special relativity and general relativity. This is not true because the corrections of the atomic clocks on the GPS satellites are absolute changes of the clocks (i.e. the same observed in all reference frames), none of which is relative to a specific observer as claimed by special relativity. After all corrections, the clocks are synchronized not only relative to the ground clocks but also relative to each other, i.e., time is absolute and special relativity is wrong.

    This is a fact as shown on Wikipedia. But some people still argue that the clocks on the GPS satellites are only synchronized in the earth centered inertial reference frame, and are not synchronized in the reference frames of the GPS satellites. If it were true, then the time difference between a clock on a GPS satellite and a clock on the ground observed in the satellite reference frame would monotonically grow due to their relative velocity while the same clocks observed on the earth centered reference frame were still synchronized. If you corrected the clock on the satellite when the difference became significant, the correction would break the synchronization of the clocks observed in the earth centered frame. That is, there is no way to make such a correction without breaking the synchronization of the clocks observed in the earth centered frame. Therefore, it is wrong to think that the clocks are not synchronized in the satellite frame.

    Hefele-Keating experiment is also considered as another evidence of relativistic effects. It is clear that all the differences of the clocks after flights in Hefele-Keating experiment were absolute (i.e., they were the same no matter whether you observe them on the earth, on the moon or on the space station). But according to relativity, if the clocks were observed on the earth, the two clocks after flights had experienced the equivalent paths of same velocity and same distance in same elevation, and thus should generate the same kinematic time dilation and the same gravitational time dilation, directly contradicting the experimental result. Therefore, the differences of the clocks were nothing to do with the velocities relative to each other or relative to the earth as claimed by relativists, but were the result of the velocities relative to one medium which seems fully dragged by the earth on its surface but partially dragged on the altitude of the airplanes. It is wrong to interpret the differences of the displayed times of the clocks as the results of relativistic effects.

    Experiments show that electrons will emit photons when they are “moving”, but “moving” is relative. All electrons on the earth can be considered “moving” when you observe them on a rocket. According to special relativity, you should see them emit photons. Why in a rocket frame don’t you see the electrons emit photons? It is because special relativity is wrong. It is not the velocity relative to the observer which makes an electron emit photons, but it is the velocity relative to “something” makes an electron emit photons. This “something” is aether, the existence of which has been proved in the above paper. Photons are waves of aether which is a compressible viscous fluid filling up the entire visible part of the universe, though its viscosity is very very small. It is the velocity relative to aether makes an electron emit photons, just as a boat on a water generates waves only when it moves relative to the water.

    The increase of the lives of muons in particle accelerators or going through the atmosphere are the effects of aether caused by their velocities relative to aether, which are absolute changes and the same observed in all reference frames, nothing to do with relativity.

    All so-called proofs of relativistic effects are just misinterpretations of experiments and observations without exception, and all what relativity describes is irrelevant to physical phenomena, including the speed of light which in special relativity is constant in all inertial reference frames, but which in real physical world still follows Newton’s velocity addition formula (see the paper).

    That is, time is absolute and space is 3D Euclidean. There is nothing called spacetime continuum in nature, not to mention the ripples of spacetime.

    1. philip-gardner

      Mr or Ms Xin, I have tolerated your long posts before and I wonder why your name has not replaced Einsteins’, maybe because you are sincerely wrong. Einstein developed his theories through thought experiments and mathematics initially without access to computers or the vast complexes of scientific hardware and software that now strives to prove or disprove scientific thought. The theory of relativity has been continuously verified over the last ~100 years. I think the readers of S&T newsletters are a bit tired of your postellations of aether that were disproved more that 100 years ago and have not stood up to science. If it was me, I would block your access to S&T comments until you can present a sufficient number of peer reviewed papers to the scientific community that verify your arguments. Until then I’m sticking to Einstein.

      1. stub.mandrel

        He doesn’t need peer-reviewed papers, he’s issued a press release.

        I am getting to the point of ignoring all comments on this website as about 50% of them are complete nonsense.

        If this post is to be moderated, some others clearly aren’t, certainly not Mr Xin’s cut-and paste that follows any article daring to mention relativity…

      2. xinhangshen

        It’s really too bad to see those comments here which simply express their feelings rather than presenting their logical reasoning. My paper has already been published on an international peer-reviewed journal which seems the only academically recognized journal in the world with an open-mind. Don’t ask me to publish the paper on Nature, Science or other relativists controlled journals which reject papers simply based on their bias – anti-establishment without having peer-reviewing. When I asked their reasons, they told me that it is not in the interests of their readership. Do you know your statement is a deadloop if you only recognize journals such as Nature or Science as they unconditionally reject all anti-relativity papers?

        Please be aware that science is not a religion. A theory in science can be disproved through logical reasoning, but up to now I have never got any valid challenge to my paper with rigorous logic. If you indeed find any error in my comments, please refute it instead of meaningless grumbling. I will be glad to debate with all of you.

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